No, it doesn't. Where were the "shockingly old dates" - I've never seen "best before" dates on salt. It's a chemical compound (yes, even the expensive ones) that's pretty stable, as long as you store it properly it won't change over time.

Among others, I have an unopened box of Morton's Coarse Kosher Salt, undated -- and a container of fin sel gris marked on bottom w/ lot number 2900 12/2004. They have been stored in a cabinet undisturbed all these many years.

That's just when it was packed. Not a "best before" date. All salt is fine even if you've had it for years. Just if it's old and improperly stored it might be more like a block. It's still fine to use, you just might have to chip off pieces :)